Indicating means for engines having thermosiphon or other cooling systems



Jan, 5, 1925.

H. H. BOYCE INDICATING MEANS FOR ENGINES HAVING THERMOSIPHON OR OTHER COOLING SYSTEMS Filed 1918 7 and in such systems, if an ?atent Jan. 6, 1925,

. v4 HARRISON H. BOYCE, OF FORE ST HILLS, NEW YORK.

INDICATING MEANS FOR ENGINES HAVING THERMOSIPHON OR OTHER GODLING SYSTEMS.

Application filed August 2, 1918. Serial No. 247,834.

To all whom it may concern v Be it known that I, HAnuIsoN H. Boron, a citizen of the United States, residing at Forest Hills, in the county of Queens and State of New York, have invented certain new and useful Improvements in Indicating Means for Engines Having Thermosiphon or Other Cooling Systems, of which the following is a specification.

This invention relates to instruments for.

indicating the thermal condition oi? internal combustion engines of automobiles, new planes and the like. Such engines, as is well known, operate satisfactorily only within certain temperature limits, too cool a t emperature preventing satisfactory conditions for combustion and possibly resulting in freezing of the cooling water. or congealing of the lubricant, and too high a temperature causing overheating.- The latter condition is especially undesirable for if continued it will frequently result in serious damage to the engine such .as seizing of the pistons, scoring or cracking of the cylinder walls, or other injury. My present invention relates to means forming a guide for the operator of the vehicle enabling him to determine at any time the thermal condition of the engine and also constituting an eii'ective, danger signal for warning the operator of the approach of overheating conditions. In the preferred embodiment of the invention illustrated these results are accomplished by the use of an instrument combined with the water circulating cooling system of the engine. As is well known such cooling systems comprise jackets around the engine cylinders and a radiator for cooling the water, (:onnections being providedthrough. which the wateris circulated between the jackets and radiator. In many of these cooling systems a pump is utilized for producing a rapid and positive circulation of the water adequate radiator is provided, the water will usually be maintained at a temperature considerably below the boiling point. Anothervery extensively used type of cooling system, however, is that known as the thermo-siphon system in which no pump is emplo ed but in which the water is caused to circulate by. the action of gravity owing to the diiference in density of the hot water in the jackets and the cool water in the radiator. terns the circulation is usually slow and the Water leaving the cylinder jackets and passing to the radiator is very hot, often closely apprmu-hing the boiling point. The present invention is especially applicable for use in connection with thermo-s1phon cooling systems although. it may be employed in other constructions where conditions render it desirable.

When the temperature of the water in the cooling system is normally not far below the boiling point as in tlie case of thermo-siphon systems it is necessary for the danger indicating signal to be produced by a comparatively slight rise in temperature and the present invention is especially directed to In such systhe provision of means capable of acting I in this manner. The means which I employ comprise a temperature responsive element arranged to be influenced by .the'temperature in the cooling system and visual indicating means controlled from the temperature responsive means so constructed as to have a comparatively gradual movement for the changes in temperature in the lower range of the instrument or below a certain point or critical temperature and a more rapid movement athighcr temperatures. In

the preferred form of my invention I employ a glass tube thermometer type of instrument having an efl'ective cross-sectional bore area which is non-uniform so that for the lower temperatures the rise of the fluid will be gradual, thus "permitting an instrument of considerable range to be compressed .Withinsmall compass, while within the region of the higher temperatures the effecbore of the tubing is retive cross-sectional duced whereby a fluid rapid. movement of the column is obtained within such range. the accompanying drawings which form a part ofthis specification and in which a preferred embodiment of the invention has been shown as illustrative principle thereof:

Figure 1 is a diagrammatic side View of an internal combustion engine of an automobile or other vehicle provided with a cooling system of the 'thCI'lHO-SlPlIOIl type and showing the invention incorporated therein.

igure 2 is a view of the face of the indi eating instrument shown. in Figure h of the v Figure 3 is a vertical section of the thermometer tube and upper part of the casin".

Figure 4 is a transverse section ofv the thern'ioiucter tuhe near its upper end.

In both Figures 3 and l the dimensions of the parts and particularly the diameter of'thetuhe loore. are somewhat exaggerated for clearness in illustration;

Referring to the drawings in detail the numeral 1 designates an internal combustion motor having cylinders 2 surrihuuled by Water jackets These jackets are connectcd by an outlet pipe 4- With the upper part of a radiator the lower part of which is connected with a return pipe ,6 which oon- Veys the Water hack to the jackets. The cooling water 7. which in the jackets is heated By the heat of the combustion in the cvlinders, tends to rise and flows through the pipe 4 into the upper part of the rad iator. The water in the radiator which is considerably cooler than the Water in the jackets and therefore of greater densitv de scends by gravity and thus a circulation is.

set up from the iackets to the radiator and. then hack to the Jackets. As this circulation depends entirelv upon the slight differonce in the density oi the water produced hv the heating thereof. the temperature or the Water is usually high and the Water leavinL the jackets is frequently hut slightlv below the boiling point. ,qines this constitutes the normal condition of operation. A'sliaht increase in the temperature in the waten'however, so that hoilingr aotuallv occurs will ordinarilv indicate a dangerous or undesirable condition as it tends to show that there is some improper condition of operation and furthermore continued boiling results in the loss of the coolinc Water and consequently eventually in the failure of the cooling system. The hoil ing of the water therefore constitutes a condition of potential danger which my invention is designed to render at once noticeable to the operator upon its actual occurrence or even near approach.

In accordance with the preferred form of mv invention illustrated I mount in connection with the cooling system and proton ablv upon the filler cap 8 of the radiator 5 an indicatinrz instrument 9 the construction of which will now he described. As illustrated the instrument comprises a suitable frame securedon tho filler cap and carryingv dial plate 10 havinn' a danger zone indieating means preferably in the form of a window 11 in the dial plate. Also mounted in the "frame is a. class thermometer tuhc 12 which extends vertically in "front oi the dial plate and which is proyideri at its lower end with a. bull 13 of usual construction adapted to extend through an opening in the radiator cap into the radiator. The hulh of the thermometer being influenced by the reasons. 1: therefore have producm In manv en-.

high that the normal reading of the tortmomcter may he very near the boiling point and as the instrument usually located on the radiator at some little distance in irou of the driver, the. slight: rise in the coluum Which will occur upon the actual boiling: otthe Water may he diihoult oi discernment it the ordinary type of thermometer tube used It is not feasible to overcome this condition by utilizing a thermometer hav ion a long: tube and an even scale througslk y out as such a thermometer obviously would he undesirahle on a. vehicle tor 2r i so constructed as to give a very rapid more incnt ot the column at and near the boil a point. In this Way a comparativel sh .L' thermometer tuhe may be employed which will nevertheless cover the entire range om fre zing to boiling? and will also yield an extensive and easily ohservahle movement hore. The expansioi'i of the liquid in huih 13 which is substantially constant for equal changes in temperature will prod a given gradual rate of rise of the coin in the tnhe 12 up to the lower and of wire 15. Anv further increese in the pcrature oi. the hulh will produce A more rapid rise in the column from point as the volume of the hora to he till ov the liquid. in much less per unit oi T Y For instance. the tuhe '12 may have t i e 15 extended downwardly from the top of the tube about one third of the length oil the exposed portion of the tuhe and distance substantially corresponding with. the diameter of the window 11. By selecting; tuhingancl a wire of proper dimensions an instrument may he produced having a reading exteiuling from 39 F. or treezinsr to a proximately 200 at the bottom oi the wire. the rei'naininu upper range of th sole responding; to temperatures between ti" and 212". With this construction comp-u lively slight changes of temperature in cuss of Q00 easily noticeable and merits ofthe fluid column are produced. it

may easily be read by the driver of the vehicle from his seat, so as to serve as an effective warning of the approach of dangerous conditions.

While I have illustrated and described in detail one preferred embodiment of my invention it will be understood that modifications may be made therein and I do not therefore intend to limit myself to such specific embodiment but desire to cover my invention broadly in whatever form its principle may be utilized.

Having thus described my invention I claim:

1. For use with a cooling system for an internal combustion engine, a temperature responsive indicating instrument containing a movable temperature indicating element, and means for causing said element to move at a faster rate when responding to the higher temperatures than when responding to the lower temperatures.

2. For use with a thermo-siphon cooling system for an internal combustion engine, a temperature indicating instrument containing a movable temperature indicating eiement and means for causing said element to move at a faster rate when indicatin temperatures above approximately 200 than when indicating temperatures below that temperature.

3. A temperature indicating instrument having a movable temperature indicating element, and means for causing said ele: ment to move at a substantially uniform rate when indicating one range of temperatures and at a different substantially uniform rate when indicating another range of temperatures. v

4. A temperature indicating instrument containing a movable temperature indicating element in liquid form, and a tube in which said liquid rises and falls having a. smaller effective cross-sectional bore area in the portion which indicates the higher temperatu'res'than in the portion which indicates the lower temperatures.

5. A temperature indicating instrument having a movable temperature indicating element in liquid form, a tube in which said liquid'rises and falls, and a filler in the upper portion of said tube for decreasing the effective cross-sectional bore area of the latter and thereb increasing the rate of movement of the liquid in the upper portion of the tube.

HARRISON H. BOYCE.

' 1 Certificate of Correction. It is hereby certified that in Letters Patent No. 1,521,992, granted January 6,

1925 upon the appiication of Harrison H. Boyce. of Forest an improvement in Indicating Means Hills. New York, for for Englnes Having Thermosiphon or Other Cooling Systems, an error appears in the printed specification requiring correction as follows: Page 3, line 18, claim 1, after the Word temperature insert the word responsive; and that this :irrection therein that I Qfiice.

and sealed this 10th day of February,'A. D.

the said Letters'Patent should be read with the same may conform to the record of the case in the KARL FENNING, Acting Uommz'aaa'oner of Patents; 

